12.12.2007

It’s amazing to me that cars don’t tell you the inside temperature. Just about every car I drive has an exterior thermometer. But where’s the interior one?

An exterior thermometer appears to be the new standard feature. My Mazda3 hatchback has one, as does my wife’s Acura TSX. My wife’s previous car, a 1999 BMW 528i (aka, “the piece of junk that spent all its time in the shop”) had an exterior thermometer, too.

The BMW would even chime if the outside temperature dropped enough to present a danger of road ice, which was handy if you were driving from San Francisco to Lake Tahoe in the winter.

But no inside thermometer.

Now, the cars know what temperature it is inside. The BMW, the Acura and my little Mazda all have digital climate-control systems, where you set the temperature and the car holds it. The computer has to know the temperature in order for that to work.

The displays will therefore show you two piece of data:

1. What the outdoor temperature is (which the Mazda calls the “ambient temperature”).

2. What temperature you have set the climate control system for.

However, they will not show you the inside temperature. Even the super-sophisticated computer in the Acura TSX won’t divulge this secret, though it tells you just about everything else.

Thus, when you step into the car, you don’t know if the interior is 130 degrees (sitting in the sun with all the windows closed), -10 degrees (sitting all night at Lake Tahoe), or a slightly warm 85 degrees.

Why not? It’s a mystery. (And I know that there are some cars that do tell you the indoor temperature. I’ve rented a few of them. However, the overwhelming majority do not display the interior temperature.)

The solution? Go to the local auto-parts store and pick up a cheap digital or analog thermometer and stick it somewhere on the dashboard where it’s not going to be in direct sunlight most of the time. Pictured is the model that we purchased for each car; it costs nine bucks from Amazon. Isn’t it bizarre that carmakers leave this out?

2 comments:

Gosh, I have NO IDEA what the temperature is of the interior of my car in Death Valley in the summer. Excuse me?

The reason there is no indoor themometer is that it is irrelevant - your're either cold, or hot, or pleasantly gruntled. If the thermometer read 74 degrees but you felt cold would you not put on the heat because the thermometer in effect told you so?

This is a classic example of what is wrong with many products. Just because you CAN engineer something, doesn't mean you SHOULD. In this case carmakers haven't succumbed to that sort of thinking (lord knows they have in so many other ways like obnoxious, distracting GPS's and maddening digital radio tuners). Thank goodness!

About Me

Co-founder and editorial director of BZ Media, which publishes SD Times, the leading magazine for the software development industry.
Founder of SPTechCon: The SharePoint Technology Conference, AnDevCon: The Android Developer Conference, and Big Data TechCon.
Also president and principal analyst of Camden Associates, an IT consulting and analyst firm.